[sdiy] 3046 vco help?

[Dan Snazelle]

I have been messing around with the EFM 3046 vco 

http://www.modular.fonik.de/files/EFMforum/orgEFMfiles/3046_VCO.pdf




i would love to understand how the core circuit works.

(minus the square shaper)


I see 2 differential amps, a fet, a cap and a pnp....how does it work though?


I figure if i could get my head around a simple core like this transistor core, it might make understanding other discrete vcos easier to grasp.


Thanks for any help!

Sent from my iPhone